One-pot synthesized inverse-structured CeO₂/Ni catalysts for enhanced low-temperature CO₂ methanation via...

Conventional Ni-based catalysts often exhibit limited metal-support interactions (MSI) and limited density of active interfacial sites, which significantly restrict their low-temperature activity for CO₂ methanation. In this study, we report a binary inverse-structured CeO₂/Ni catalyst synthesized via a facile one-pot sol-gel method. The optimal 10% CeO₂/Ni catalyst achieved a CO₂ conversion of 85.4 ± 0.5% with 98.8 ± 0.2% CH₄ selectivity at 200 °C under a gas hourly space velocity of 12,000 mL·g_cat^-1·h^-1 during 150 h long-term stability test, substantially outperforming the conventional 10% Ni/CeO₂ catalyst. Comprehensive characterizations collectively indicate that the enhanced low-temperature performance arises from synergistic effects induced by the inverse architecture. The MSI facilitates hydrogen spillover from metallic Ni to CeO₂, while enriched interfacial oxygen vacancies provide abundant active sites for CO₂ adsorption and activation. In-situ diffuse reflectance infrared Fourier transform spectroscopy results further suggest that the inverse structure steers the reaction toward a highly efficient formate-mediated pathway. This work highlights structural inversion as a facile and effective design strategy to reinforce MSI, offering a promising approach for developing high-efficiency low-temperature CO₂ hydrogenation catalysts.